Merge pull request #355 from googlecodelabs/preview-issue

Fix small issue with the google preview button

Author: skarEE

codelab-elements/google-codelab/google_codelab.js

@@ -756,6 +756,7 @@ class Codelab extends HTMLElement {
           if ('userfeedback' in window) {
             window['userfeedback']['api']['startFeedback']
                 ({'productId': '5143948'});
+            e.preventDefault();
           }
         });
     }